make CheckDiskSpace() use a global static const uint64 for checking required disk space and remove 2 ugly spaces from a message string
Get rid of snprintf (except one) with fixed buffers, shorten code

- Use strprintf or vstrprintf instead of snprintf
allow translation of "options" used in the --help message / split translation of RPC console welcome message and remove the need to take care of "<br>" / remove some spaces in strings and misc other stuff related to translations
Refactor: move code from key.h to key.cpp
Refactor: GetRandHash() method for util
Was showing a negative number. Changes to positive, since negative (T minus) usually indicates a future event.
JSON-RPC: remove 'getblocknumber' deprecated RPC

RPC 'getblockcount' should be used instead.
add an icon for Debug logfile -> Open in the RPC console / add a missing comment in rpcconsole.h
Update License in File Headers

I originally created a pull to replace the "COPYING" in crypter.cpp and
crypter.h, but it turned out that COPYING was actually the correct
file.
Optimize orphan transaction handling

Changes suggested by Sergio Demian Lerner to
help prevent potential DoS attacks.
Remove invalid dependent orphans from memory

Remove orphan transactions from memory once
all of their parent transactions are received
and they're still not valid.
Thanks to Sergio Demian Lerner for suggesting this fix.
Further DoS prevention: Verify signatures last

Loop over all inputs doing inexpensive validity checks first,
and then loop over them a second time doing expensive signature
checks. This helps prevent possible CPU exhaustion attacks
where an attacker tries to make a victim waste time checking
signatures for invalid transactions.
Cache signature verifications

Create a maximum-10MB signature verification result cache.
This should almost double the number of transactions that
can be processed on a given CPU, because before this change
ECDSA signatures were verified when transactions were added
to the memory pool and then again when they appeared in
a block.
Merge pull request #1350 from jgarzik/del-deprecated

JSON-RPC: remove 'getblocknumber' deprecated RPC
change strings to Bitcoin (uppercase), where it is used as a noun and update strings to use "Qt" (and not qt or QT) / update initialisation of notificator to use qApp->applicationName() instead of a static string
Serialize access to debug.log stream

Acquire an exclusive, advisory lock before sending output to debug.log
and release it when we're done. This should avoid output from multiple
threads being interspersed in the log file.

We can't use CRITICAL_SECTION machinery for this because the debug log
is written during startup and shutdown when that machinery is not
available.

(Thanks to Gavin for pointing out the CRITICAL_SECTION problems based
on his earlier work in this area)
Reopen debug.log on SIGHUP

The best log rotation method formerly available was to configure
logrotate with the copytruncate option.  As described in the logrotate
documentation, "there is a very small time slice between copying the
file and truncating it, so some logging data might be lost".

By sending SIGHUP to the server process, one can now reopen the debug
log file without losing any data.
Shared code for wallet lock help and check
Default to DB_TXN_WRITE_NOSYNC for all transactional operations

* This is safer than DB_TXN_NOSYNC, and does not appear to impact
  performance.
* Applying this to the dbenv is necessary to avoid many fdatasync(2)
  calls on db 5.x
* We carefully and thoroughly flush databases upon shutdown and
  other important events already.
Replace debug window icon with LGPL-licensed one (fixes #1348)